Opacifier latices



United States Patent ()fiice 3,503,892 Patented Mar. 31, 1970 3,503,892 OPACIFIER LATICES Philip L. Weyna, Crystal Lake, Douglas Woodrutf,

Marengo, and Volney P. Thuma, Woodstock, 11]., assignors t Morton International, Inc., Chicago, 11]., a corporation of Delaware No Drawing. Filed Apr. 28, 1966, Ser. No. 545,829 Int. Cl. Clld 3/20; C08f 19/12 U.S. Cl. 252-161 3 Claims ABSTRACT OF THE DISCLOSURE A novel aqueous base copolymer latex containing a major proportion of styrene and/or methylated styrene and a minor proportion of the reaction product of polyalkylene glycol and maleic anhydride for use as an opacifier, the process of preparing said aqueous base copolymer latex, and a stabilized opacified detergent composition comprising a surface active agent and said aqueous base copolymer latex.

This invention relates to the production of novel polymeric latices of the type useful in opacifying aqueous liquid detergent compositions, to opacified detergent compositions made therefrom, and to the process of opacifying aqueous liquid detergent compositions. More particularly, this invention relates to the production of novel polymeric latices of the type useful in opacifying aqueous liquid detergent compositions containing biodegradable surfactants, to opacified biodegradable detergent compositions made therefrom, and to the process of opacifying aqueous liquid biodegradable detergent compositions.

An aqueous liquid detergent composition, as the term is used herein, is one containing water, a surface active agent and optionally one or more of the following ingredients: a foam stabilizer, a foam booster, a small amount of a hydrotrope, e.g. sodium benzene sulfonate, sodium toluene sulfonate, sodium xylene sulfonate and/ or alcohol. Usually the whole composition is adjusted to a neutral pH. The above type composition is often characterized as a light-duty liquid detergent. A so-called general-purpose or a heavy-duty liquid detergent may contain, in addition, one or more of the so-called alkaline boosters, such as alkali metal silicates, carbonates, polyphosphates and the like. Aqueous liquid detergents are used extensively in dish washing, laundering, bathing, and in general purpose cleaning preparations. They are usually clear in appearance and have varying degrees of viscosity.

Dyes and particularly opacifying agents are conventionally added to these products to improve their attractiveness to consumers, who, through long exposure to cosmetic products in the form of creams and lotions, have come to associate a creamy or opaque, milky appearance with mildness, softness and luxuriousness.

.Polymer latices of varying compositions have been used to opacify detergent formulations. However, many liquid detergents, particularly those composed of biodegradable surface active agents, display poor storage stability when opacified with conventional polymer latices. This instability is characterized by polymer separation with the deposition of a sludge-like material which destroys the attractiveness of the product and thereby defeats the original objective.

It would, therefore, be desirable to provide improved polymer latices which have utility in the production of stable, opacified liquid detergent compositions, particularly those detergent compositions containing biodegradable surface active agents.

Accordingly, one object of this invention is the provision of novel polymer latices for use in opacifying liquid detergent compositions.

Another object of this invention is the provision of novel polymer latices for use in opacifying liquid biodegradable detergent compositions.

Still another object of this invention is the provision of a process for producing improved opacifier latices.

A further object is the provision of stable, opacified liquid detergents containing various concentrations of biodegradable surface active agents.

Another object of this invention is the provision of polymer latices which are useful in opacifying liquid detergent compositions containing a hydrotrope.

Still another object is the provision of polymer latices for use in opacifying cosmetic preparations, commercial cleaning and bleaching preparations such as, for example, toilet bowl cleaners, liquid laundry bleaches and household ammonia.

A still further object of this invention is the provision of a process for opacifying liquid detergent compositions.

The fulfillment of these and other objects of the present invention may be better understood by reference to the following specification and appended claims.

Accordingly, in one broad form, the present invention comprises a copolymer latex, said copolymer containing in polymerized form ingredients comprising a major proportion of a monomer selected from the group consisting of a styrene and methylated styrene, and a minor proportion of the reaction product of a polyalkylene glycol, such as polyethylene glycol and maleic anhydride. More particularly, the copolymer contains in polymerized form ingredients comprising from about 50 to about percent by weight of a monomer selected from the group consisting of styrene and methylated styrenes, and from about 15 to about 50 percent by weight of the reaction product of polyalkylene glycol and maleic anhydride, the proportions of the foregoing ingredients being selected to total percent.

The polymerization procedure of the present invention employed to prepare the herein described latices is an aqueous emulsion polymerization technique utilizing free radical or peroxide type catalysts. It is possible to prepare the present opacifier latices by either a one or a two phase monomer addition procedure, however a two phase monomer addition procedure is preferred, as it results in a latex which imparts greater storage stability to an opacified liquid detergent in which it is incorporated than does that prepared by a one monomer phase addition.

Unsaturated monomeric aliphatic carboxylic acids, such as methacrylic acid, acrylic acid and itaconic acid, may also be used as additional comonomers in preparing the copolymer latex compositions of the present invention. Although not an essential component of the copolymer latices of this invention, the unsaturated acids function to impart freeze-thaw and mechanical stability to the resultant latex. When so used, they are employed in proportions of from about 2 to about 4 parts by weight on a 100 parts of total monomer basis.

In one preferred form the present invention is a process for producing the herein described copolymer latex which comprises carrying out said polymerization by dividing said monomer into two fractions wherein the first contains a portion of the total of a monomer of the group consisting of styrene and methylated styrene admixed with substantially all of the unsaturated acid monomer, said first fraction being added as a first monomer phase to an aqueous polymerization medium containing a surface active agent and a free radical catalyst, and upon completion of the addition of the said first monomer fraction, adding a second monomer fraction containing the remainder of the total of a monomer selected from the group consisting of styrene and methylated styrene admixed with substantially all of the reaction product of polyalkaline glycol and maleic anhydride.

The copolymer latex product preferably has a solids content of from about 30 to 50 percent by Weight on a total latex basis.

Another form of the present invention is a stable opacified aqueous liquid detergent composition containing a detergent selected from the group consisting of anionic and nonionic surface active agents, particularly biodegradable anionic and nonionic surface active agents, and an opacifying latex as above defined. Of particular interest are detergent compositions which contain solubilizing acids and/or hydrotropes. The term detergent or surface active agent also includes specific surface active agents which are known to the art as foam boosters and/ or stabilizers for their particular function in the deand having a theoretical acid number of about 110 in the instance of polyethylene glycol having a molecular weight of 400 to the diester having an essentially zero acid number and represented by the following generalized tergent formulation. Preferably'the opacifier is present structure:

(on a solids basis) in amounts of from 0.1 to 14 parts per 100 parts of surface active agent. Expressed as percentages, one specific group of detergent formulations may contain the following:

Percent by weight Surface active agent (including detergent, foam booster and/or foam stabilizer) 18-55 Hydrotrope 1-15 Water 6080 Opacifier latex (-50% solids) .1-5

Anionic and nonionic surface active agents utilized in the opacified liquid detergents of the present invention include sodium dodecylbenzene sulfonate, alkali salts of complex organic phosphate esters, alkyl aryl sulfonates, sodium lauryl ether sulfates, sodium lauryl sulfate, the octyl and nonyl phenoxy (polyethyleneoxy) ethanols, polyoxyakylene ethanols, polyoxyethylene sorbitan fatty acids and fatty acid alkanolamides, and the like.

Although, as previously pointed out, the latices herein described are particularly useful in opacifying liquid detergents containing biodegradable surfactants, it should be noted that they are also effective in opacifying conventional light duty and heavy duty liquid detergents, shampoos, hairwaving solutions, liquid toilet bowl cleaners, laundry bleaching liquids and household ammonia, which compositions conventionally contain materials which adversely affect the stability of ordinary opacifying latices.

In the copolymer latex compositions of the present invention the monomers may be present in varying amounts. In the preferred aspects of this invention, monomers selected from the group consisting of styrene and methylated styrene are present in amounts of from about 50 to about 85 parts 'by weight per 100 parts of total monomer and most preferably from about 60 to about 80 parts by weight on the same basis. Of the aforesaid monomers, styrene is preferred. Exemplary of the methylated styrene monomers useful in preparing the interpolymer latices of the present invention are monomethyl styrenes, such as 4-methyl styrenes (also known as vinyl toluene), and dimethyl styrenes, such as 2,4-dimethyl styrene. It should be understood that mixtures of styrene and/ or methylated styrenes can also be used.

The polyalkylene glycols which are employed in producing the reaction product with maleic anhydride are polymers exemplified by the following general formula:

where R is of the group of hydrogen, methyl or ethyl and n is an integer from 4 to 20, corresponding to molecular weights ranging from about 200 to about 1000 or To make the polyethylene glycol-maleic anhydride reaction products used in the opacifier latices of the present invention, the following procdure is followed:

To a 500 ml. flask equipped with stirrer and thermometer are added 78 grams (0.8 mole) of maleic anhydride and 321.4 grams (0.8 mole) of polyethylene glycol having a molecular weight of about 400. One gram of sulfuric acid is added to catalyze the reaction and the mixture is heated to about 75 C. while stirring continuously. The course of the reaction is followed by determining the acid number of the reaction mixture at intervals. The admixture is cooled to stop the reaction at the desired acid value.

The acid number is determined as follows:

A l-gram sample of the product mixture is accurately Weighed and dissolved in 100 ml. of water. The resultant solution is titrated with 0.1 -'N KOH to a phenolphthalein end point.

Acid No cc. KOH N 56 Sample Wt.

The type of surface active agents used in the polymerization procedure of the process of the present invention is not critical. Anionic surfactants, exemplified by alkyl aryl sulfonates and/or alkyl sulfates, may be used alone or in blends with nonionic surfactants, in amounts ranging from about 1 to 1 0 percent on a total monomer basis. The time of polymerization is likewise not critical and it should be understood that by utilizing certain catalyst systems, such as, for example, redox systems, the polymerization may be carried out in a relatively short time. Accordingly, the time of polymerization may extend from about 15 to about 240 minutes, although for most purposes from about 30 to 180 minutes are adequate.

In the preferred process of the present invention, a two phase monomer addition procedure is employed in which from about 15 to about 80 percent by weight of the total styrene or methylated styrene and 100 percent by weight of the total unsaturated acid monomer are added as a first monomer phase or fraction to a reaction vessel containing water, a surface active agent, and a free radical catlyst. Upon completion of the addition of the first monomer phase, a second monomer phase or fraction containing the balance of the total styrene or methylated styrene, i.e., from about 20 to about percent of the total styrene or methylated styrene used and 100 percent by weight of the reaction product of polyethylene glycol and maleic anhydride is added. The temperature is maintained at about 80 to C. until completion of the monomer addition. Upon completion of the reaction, the pH is adjusted to about 8 with a solution of sodium hydroxide. It should be understood that the parts by weight or percentages referred to herein MgKOH/g. sample have reference to monomeric constituents only and do not include diluents, carriers, additives, or other materials which may be used in conjunction with the monomers in the polymerization process.

For a more complete understanding of the present invention, reference is now made to the following specific examples which are illustrative of the preparation of the various copolymer latices, their evaluation as opacifiers for liquid detergent compositions containing biodegradable surface active agents and opacified detergent compositions.

The kettle charge is added to a suitable vessel equipped with reflux condenser, mechanical stirrer, addition funnel and thermometer. The charge is heated to 8890 C. When the charge reaches this temperature, the catalyst is added with continuous stirring. Upon completion of the addition of the catalyst, the monomer phase is added to the stirred reaction medium at a uniform rate over a period of about 80 minutes. The entire reaction is carried out at a temperature ranging between about 85 and 95 C. Stirring and heating at this temperature is continued for about 30 minutes after the completion of the monomer phase, after which the batch is cooled, treated with sodium hydroxide solution to effect a pH of 8 and then filtered to produce the finished product.

EVALUATION OF OPACIFIED DETERGENT STABILITY To evaluate the stability of a typical liquid detergent opacified with the composition of Example 1, the following three liquid detergent compositions were employed in this as well as in tests hereinafter described as representative of typical aqueous light-duty liquid detergents containing diodegradable surface active agents as well as non-biodegradable surface active agents.

Detergent composition A Percent by weight n-Alkyl sodium alkylbenzene sulfonate (58% active), commercially available under the trade name C-560 Slurry Sodium salt of the sulfate ester of ethoxylated primary alcohols (59.8% active), commercially Isooctyl phenyl polyethoxy ethanol (100% active), commercially available under the trade name Triton X-10 10.5

Deionized water 5.3

pH adjusted to 7.0 with sulfuric acid.

Detergent composition C Sodium salt of straight chain alkyl aryl sulfonate (35 active), commercially available under the trade name Nacconol 35SL 85.0 Sodium lauryl sulfoacetate (97% active) 5.0 Isooctyl phenyl polyethoxy ethanol (100% active),

commercially available under the trade name Triton X-102 10.0 pH adjusted to 7 .0 with sodium hydroxide.

Cne part by weight of opacifier latex prepared as described in Example 1 is dispersed in 4 parts by weight of ion exchanged water. This entire latex dispersion is then added to 95 parts by weight of detergent composition A with stirring. Detergent compositions B and C are similarly opacified. This produces a stable, opaque, milky lotion-like liquid which is tested for stability by storage of aliquots at room temperature, 45 F. and F. In addition, the opacified detergent compositions are subjected to repeated cycles of freezing and thawing. A rating of excellent is given when no sign of instability is seen at the end of thirty days. A rating of good indicates only a slight ring or cloudiness at the end of the thirty days. A rating of fair shows stability for a limited time, i.e. more than one day but less than one week.

The results obtained for Example 1 evaluated as above are:

Example 1 Detergent A, Good Detergent B, Fair Detergent C, Good Examples 2 through 13 illustrate a two monomer phase addition procedure.

EXAMPLE 2 Parts by Weight per 100 Parts by Parts Total Kettle Charge Weight Monomer Water 740 Catalyst 1: Ammonium persulfate 3. 0

Monomer phase A:

Styrene 224 37.3

Methaerylic acid 16 2. 7

Ammonium salt of the sulfate ester of nonylphenoxypoly (ethyleneoxy) ethanol [58% active] 2. 0 Nonylphenoxypoly (ethyleneoxy) ethanol 4.0

Monomer phase B:

Styrene 30. 0

Polyethylene glycol (molecular weight 400)-maleic anhydride reaction product (acid number 9 180 30.0 Ammonium salt of the sulfate ester nonylphenoxypoly (ethyleneoxy) ethanol [58% active] 10 Catalyst 2:

Ammonium persulfate 1. 0

Ammonium salt of the sulfate ester of nonylphenoxypoly (ethyleneoxy) ethanol [58% active] 2. 0 Deionized water 20 The kettle charge is added to a suitable vessel equipped with reflux condenser, mechanical stirrer, addition funnel and thermometer.

The charge is heated to 9092 C. with continuos stirring. When the charge reaches this temperature, catalyst 1 is added with stirring. Upon completion of the addition of catalyst l, monomer phase A is added to the stirred reaction medium at a uniform rate over a period of about 75 minutes. After the addition of monomer phase A, /2 of catalyst 2 is added and the addition of monomer phase B is begun at a constant rate over a period of about 75 minutes. The other half of catalyst 2 is added when the addition of one-half of monomer phase B is completed. The entire reaction is carried out at temperatures varying between 85 C. and 95 C. Stirring and heating at this temperature is continued for about 60 minutes after the completion of the addition of monomer phase B, after which the batch is cooled, treated with sodium hydroxide 7 solution to effect a pH of 8 and then filtered to form the finished product.

The results obtained for Example 2 when evaluated as an opacifier according to the hereinbefore described procedure are:

Example 2 Detergent A, Excellent Detergent B, Fair Detergent C, Good Copolymer latices Examples 3 through 13, are prepared as set forth in Example 2 and evaluated as above, with the exception that the following changes in the copolymer latex composition are made as indicated.

EXAMPLE 3 Change:

The acid number of the polyethylene glycol-maleic anhydride reaction product is 79.

EXAMPLE 4- Change:

(1) The acid number of the polyethylene glycolmaleic anhydride reaction product is 25. (2) The ratio of the number of moles of maleic anhydride to the number of moles of polyethylene glycol is as 0.69 is to 1.

EXAMPLE 5 Change:

(1) The acid number of the polyethylene glycolmaleic anhydride reaction product is 11. (2) The ratio of the number of moles of maleic anhydride to the number of moles of polyethylene glycol is as 0.5 is to 1.

EXAMPLE 6 Change:

(1) The acid number of the polyethylene glycolmaleic anhydride reaction product is 69.

(2) The molecular weight of polyethylene glycol used is 600.

EXAMPLE 7 Change:

(1) The acid number of the polyethylene glycolmaleic anhydride reaction product is 50. (2) The molecular weight of polyethylene glycol used The table sets forth the results of the evaluation of the foregoing compositions as opacifiers in accordance with the aforedescribed procedure:

TABLE Detergent A Detergent B Detergent 0 Excellent.

Example Fxnellenf From the foregoing examples it may be seen that the novel copolymersof the present invention result in latices which are particularly useful in opacifying aqueous detergent compositions containing biodegradable surfactants. Examples 1 through 12 illustrate the scope and range of the operable compositions of the present invention.

Example 13 illustrates the essentiality of the polyethylene glycol-maleic anhydride reaction product to the latex composition as an effective opacifier.

While several particular embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

We claim:

1. A process for preparing a copolymer latex, said latex comprising in polymerized form per 100 parts of copolymer from about 50 to about percent by weight of a monomer selected from the group consisting of styrene and methylated styrene, and from about 15 to about 50 percent by weight of half ester or diester reaction product of the formula:

HC=CH 0:2] :0

H!) -CHzCHrO (CHZCHOMOH CHZOBI having an acid number of from zero to about 110 prepared by reaction of from 1 to 2 moles of a polyalkylene glycol of the formula:

where R is of the group of hydrogen, methyl or ethyl and n is an integer from 4 to 20 corresponding to molecular weights of from about 200 to about 1000 per mole of maleic anhydride; said process comprising adding and polymerizing in an aqueous copolymerization reaction a first monomer fraction comprising a portion of the total of said styrene monomers, and thereafter adding and polymerizing in the course of said aqueous copolymerization reaction a second monomer fraction comprising an admixture of the remainder of the total of said styrene monomers and substantially all of said reaction product of polyalkylene glycol and maleic anhydride.

2. A stabilized opacified detergent composition consisting essentially of at least one surface active agent selected from the group consisting of sodium alkyl benzene solfonate, the sodium salts of the sulfate esters of ethoxylated primary alcohols, the octyl and nonyl phenoxy (polyethyleneoxy) ethanols, polyoxyethylene sorbitan fatty acids, fatty acid alkanol amides, alkyl aryl sufonates, sodium lauryl ether sulfates, sodium lauryl sulfate, ethylene oxide adducts of alkyl phenols, alkali salts of complex phosphate esters, ethylene oxide adducts of straight chain fatty alcohols and sodium lauryl sulfoselected from the group consisting of sodium alkyl benzene sulfonate, the sodium salts of the sulfate esters of ethoxylated primary alcohols, the octyl and nonyl phenoxy (polyethyleneoxy) ethanols, polyoxyethylene ethanols, polyoxyethylene sorbitan fatty acids, fatty acid alkonal amides, alkyl aryl sulfonates, sodium lauryl ether sulfates, sodium lauryl sulfate, ethylene oxide adducts of alkyl phenols, alkali salts of complex phosphate esters, ethylene oxide adducts of straight chain fatty alcohols and sodium lauryl sulfoacetate, in admixture with a copolymer latex, said latex being present in an amount from 0.1 to 14 parts of polymer solids per 100 parts by weight of surface active agent, said latex comprising a copolymer containing from about 50 to about 85 percent by Weight of a monomer selected from the group consisting of styrene and methylated styrene and from about 15 to about 50 percent by weight of the half ester or diester reaction product of the formula:

having an acid number of from zero to about 110 prepared by reaction of from 1 to 2 moles of a polyalkylene glycol of the formula:

where R is of the group of hydrogen, methyl or ethyl and n is an integer from 4 to 20 corresponding to molecular weights of from about 200 to about 1000 per mole of maleic anhydride.

| HOCH2CH2(OH2(IJHO) nOCHZCHZO ACHzCHz-O (OHKIJHOMOH OHzOH having an acid number of from zero to about 110 prepared by reaction of from 1 to 2 moles of a polyalkylene glycol of the formula:

where R is of the group of hydrogen, methyl or ethyl and n is an integer from 4 to 20 corresponding to molecular weights of from about 200 to about 1000 per mole of maleic anhydride.

3. A stabilized opacified detergent composition con- References Cited UNITED STATES PATENTS 2,443,735 6/1948 Kropa 260861 2,505,353 4/ 1950 Fisk. 2,521,575 9/1950 Fisk 260-861 3,207,718 9/ 1965 Zimmerman et al.

FOREIGN PATENTS 591,533 1/ 1960 Canada.

SAMUEL H. BLECH, Primary Examiner H. ROBERTS, Assistant Examiner U.S. Cl. X.R.

sisting essentially of at least one surface active agent 252-137, 138, 152; 260-296, 78.5, 861

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 1,503,892 Dated MARCH 31 1970' Inventor(s)PHILIP L. WEYNA DOUGLAS WOODRUFF and VOINEY F. THUMA It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 3, line 11 "acids" should be --aids--;

Col. 3, line l l After or" insert --foam- Col. line 10 "CH (last occurrence): the "2" 1s upside down;

001. 5, Example 1 Last line under column Kettle Charge" after "ethyleneoxy" insert closing parenthesis 001, 5, line n "diodegradable" should be biodegradable-- Claim 1 Col. 8, second part of formula, last line CH 0" (second occurrence) should be --CH 0-- Claim 2, line 6 After "polyoxyethylene" insert --ethanols polyoxyethylene Claim 2, last line of first part of formula "(J-CH2" should be --0CH 316N553 AND SEALED (SEAL) SB 15ml Am Edmunmh It.

mm B- SCIHUYLER, JR Attestmg Offiw Gflllissioncr of Patents FORM PO-IOSO (10-69) USCOMM-DC scam-ps9 9 U 5 GOVERNMENT IHINYING OFFICE I959 O-jGfi-Jll 

